Chitwood D J, McClure M A, Feldlaufer M F, Lusby W R, Oliver T E
J Nematol. 1987 Jul;19(3):352-60.
Free and esterified sterols of eggs of the root-knot nematodes Meloidogyne incognita races 2 and 3 and M. arenaria race 1 were isolated and identified by gas-liquid chromatography-mass spectrometry. The major sterols of eggs of each race were 24-ethylcholesterol (33.4-38.8% of total sterol), 24-ethylcholestanol (18.3-25.3%), 24-methylcholesterol (8.6-11.7%), 24-methylcholestanol (7.7-12.5%), and cholesterol (4.6-11.6%). Consequently, the major metabolic transformation performed by Meloidogyne females or eggs upon host sterols appeared to be saturation of the sterol nucleus. The free and esterified sterols of the same race did not differ appreciably, except for a slight enrichment of the steryl esters in cholesterol. Although the sterol composition of Meloidogyne eggs differed from that of other life stages of other genera of plant-parasitic nematodes, the three Meloidogyne races could not be distinguished from each other by their egg sterols. Ecdysteroids, compounds with hormonal function in insects, were not detected by radioimmunoassay in the Meloidogyne eggs either as free ecdysteroids or as polar conjugates.
利用气液色谱 - 质谱联用技术分离并鉴定了南方根结线虫2号和3号小种以及花生根结线虫1号小种卵中的游离甾醇和酯化甾醇。每个小种卵中的主要甾醇为24 - 乙基胆固醇（占总甾醇的33.4 - 38.8%）、24 - 乙基胆甾烷醇（18.3 - 25.3%）、24 - 甲基胆固醇（8.6 - 11.7%）、24 - 甲基胆甾烷醇（7.7 - 12.5%）和胆固醇（4.6 - 11.6%）。因此，根结线虫雌虫或卵对宿主甾醇进行的主要代谢转化似乎是甾醇核的饱和。同一小种的游离甾醇和酯化甾醇没有明显差异，只是甾醇酯中的胆固醇略有富集。虽然根结线虫卵的甾醇组成与其他植物寄生线虫属的其他生命阶段不同，但这三个根结线虫小种无法通过其卵甾醇相互区分。在根结线虫卵中，无论是游离蜕皮甾体还是极性缀合物，通过放射免疫测定均未检测到具有昆虫激素功能的蜕皮甾体化合物。
